Working as Senior Scientist (Soil chemistry & fertility) in Indian Council of Agricultural Research (ICAR), Ministry of Agriculture, Govt. of India since 2010. Presently working at Division of Soil Science and Agricultural Chemistry, Indian Agricultural Research Institute (IARI), New Delhi. Done my Masters and Ph.D. from IARI, New Delhi 110012 Supervisors: Dr. D. R. Biswas Phone: +91-2692 271605 Address: ICAR-Directorate of Medicinal and Aromatic Plants Research
Boriavi 387310 Anand, Gujarat, INDIA
Sacred basil / Holy basil (Ocimum sanctum Linn) is a sacred plant widely used in pharmaceutical /... more Sacred basil / Holy basil (Ocimum sanctum Linn) is a sacred plant widely used in pharmaceutical / cosmetic industries and is known for its varied medicinal properties. In order to study the influence of organic sources of nutrients on growth, yield and quality of sacred basil (Purple type), a field experiment was conducted at the ICAR-Directorate of Medicinal and Aromatic Plants Research, Boriavi, Anand, Gujarat for two consecutive seasons during 2015-2016. The experiment was devised in split plot design with three main plots (no organic/ fallow, green manuring with cowpea (Vigna unguiculata (L.) Walp.) and crop residue of cluster bean (Cyamopsis tetragonoloba L. Taub) and seven sub plots (Control / no FYM (Farm yard manure), 50% N equivalent through FYM, 75% N equivalent through FYM, 100% N equivalent through FYM, 50% N equivalent through FYM + Arka Microbial consortia (AMC), 75% N equivalent through FYM + AMC and 100% N equivalent through FYM + AMC) in three replications. Results revealed that different plant growth parameters with respect to plant height, plant spread and number of branches and yield parameters such as dry herb yield, and essential oil content of pooled mean of two harvests (5.03 t ha −1 , 1.35% and 6.79 kg ha −1 , respectively) were recorded maximum in the treatment which received cluster bean crop residue. Among sub plot treatments, application of 100% N equivalent through FYM + AMC (N fixing, P & Zn solubilising and plant growth promoting microbes) recorded maximum dry herb yield (6.30 t ha −1), essential oil content (1.71%) and essential oil yield (10.79 kg ha −1) for the pooled mean of two harvests. Application of different crop residues significantly improved organic carbon (SOC) and available nutrient contents in soil, improved available nitrogen, phosphorus and potassium contents, soil microbial biomass (MBC) and dehydrogenase activity (DHA) compared with control. With these results, it can be concluded that incorporation of cluster bean crop residue prior to transplanting and application of 100% N equivalent through FYM + Arka microbial consortia could be recommended as organic production technology in sacred basil to obtain higher herbage yield and quality.
Cultivation of medicinal plants by maintaining sustainable environment with low chemical inputs i... more Cultivation of medicinal plants by maintaining sustainable environment with low chemical inputs is attempted through a pot culture experiment by integrating the biochar prepared from lemongrass (Cymbopogon flexuosus) distillation waste and chemical fertilizers (CF) in different ratios. The objective was to find out the influence on yield, physiology and quality of Andrographis paniculata (kalmegh) herb and on soil chemical/biological properties. All the growth parameters and yield were significantly influenced by the integrated biochar and CF application. Biochar application, remarkably improved the soil carbon content, cation exchange capacity and nutrients accessibility. However, significantly higher fresh herbage yield (140.8 g plant −1) was recorded in the treatment receiving biochar (5 t ha −1) combined with recommended dose of CF (60:20:40 NPK kg ha −1). The same treatment resulted in higher soil microbial biomass C, fluorescein diacetate hydrolytic, dehydrogenase and alkaline phosphatase activity. Total phenol/flavonoid contents and antioxidant (DPPH and ABTS) activities, were higher in sole biochar treated plant and increased further in combination with CF. Sole application of biochar or CF did not have any significant influence on leaf andrographolide content, however their combination increased the content but the effects were not significant on stem andrographolide. The reduction in stomatal conductance and higher water use efficiency after biochar application indicates it's potential to mitigate water deficit stress. Results indicate that use of only biochar was not enough to improve the plant growth and soil health. Therefore, to achieve environmentally safe and quality herb production, it is recommended to use combination of biochar and CF which not only improve crop yield and quality but also improves the soil quality.
The potassium supplying capacity of the waste mica powder (WMP) was evaluated through chemical an... more The potassium supplying capacity of the waste mica powder (WMP) was evaluated through chemical and biological means. Four different size fractions of the WMP were studied in laboratory by different chemical extractants. At the same time, experiment of the plant growth was conducted in pot using K-deficient soil. The K release from the WMP by dif- ferent extractants followed an increasing trend with an increase in the fineness of the par- ticles. The highest K release was recorded by boiling 1 M HNO3 (376.4–1726.4 mg kg 1) followed by 1 M ammonium acetate (33.5–226.5 mg kg 1), 0.01 M citric acid (31.6– 158.3 mg kg 1) and water (12.0–112.0 mg kg 1) irrespective of the various size fractions. Significantly, higher cumulative K release from the WMP in successive extraction was re- corded with 1 M boiling HNO3 that predicts its slow-release property. The K release by different extractants was correlated significantly and positively with the biomass yield and K uptake by plants. 1 M boiling HNO3 extractable K showed higher correlation values with the biomass yield and K uptake. Therefore, it suggests that the extractant might be a better indicator of K supplying capacity of the WMP. The plant intervention was able to extract 32.8% of total K from the WMP simultaneously improving the exchangeable and non- exchangeable K pool in soil. These above-mentioned results conclude that plants can get access to a significant amount of K from the WMP and it could be an effective source of K in highly weathered tropical soils under K deficiency.
Low molecular weight organic acids (LMWOAs) are naturally occurred in soil, particularly in the r... more Low molecular weight organic acids (LMWOAs) are naturally occurred in soil, particularly in the rhizosphere due to microbial metabolites and secretion of root exudates. Various functional groups present in LMWOAs can play an effective role in phosphorus dissolution. In this study, potentiality of LMWOAs for phosphorous release from low-grade Indian rock phosphates (RPs) collected from Udaipur, Jhabua and Purulia was investigated under laboratory conditions. The characteristic of P release and the factors influencing P release from selected low-grade RPs by using seven LMWOAs along with two inorganic acids were also investigated. The amount of P release from RPs with di erent acids at various concentrations and equilibrium pH as well as the di erent factors of P release was also compared. Results showed that the average amounts of P released by all the organic acids from the three RPs increased with the concentration of organic acids. The amount of P release by the organic acids from the RPs followed the order, i.e. oxalic acid > citric acid > tartaric acid > formic acid > malic acid > succinic acid > acetic acid. A negative correlation was observed between P released from RPs and an equilibrium solution pH. The average amounts P released from all sources of RP ranged from 12 to 81 mmol P kg−1 by acetic acid and citric acid respectively. In addition, the nature of RPs, RP/acid solution ratio, leaching time and temperature significantly influenced the P release from RPs by organic acids. Thus, the LMWOAs could be a potential amendment for improving bio availability of P from RP.
The chemical reactivity of Indian rock phosphates (RPs) was measured by five chemical extraction ... more The chemical reactivity of Indian rock phosphates (RPs) was measured by five chemical extraction methods (i.e. water, neutral ammonium citrate (NCA), 2% citric acid (CA), 2% formic acid (FA) and absolute citrate solubility (ACS)). These measurements were assessed by agronomic response data obtained by growing ryegrass and palmarosa in two highly weathered acidic soils under pot culture experiment. The phosphorus (P) solubility value of RP measured by different methods followed the order: ACS > 2% CA > 2% FA > NAC > water. Considering triple superphosphate (TSP) as a standard reference P fertilizer, the agronomic response of RPs followed the order Udaipur RP > Jhabua RP ≥ Purulia RP > Mussorie RP. Methods based on citrate solubility (i.e. NAC, 2% CA and ACS) were significantly and positively correlated with agronomic response irrespective of the plant species and soil types. The best correlation value obtained with NCA indicated that P solubility in NAC solution may offer better prediction of agronomic effectiveness of RP in terms of biomass yield, relative agronomic efficiency (RAE) and P recovery efficiency. So, the present investigation will help to predict the agronomic effectiveness of low-grade RP based on chemical methods.
This study described a preparation of a low-cost adsorbent by entrapment of palmarosa distillatio... more This study described a preparation of a low-cost adsorbent by entrapment of palmarosa distillation wastes into alginate as supporting matrix and use of it for methylene blue (MB) dye removal from aqueous solution. Fourier transform infra- red spectroscopy (FTIR) data of adsorbent confirms the entrapment for formation of composite beads. The effects of adsorption parameters (adsorbent dose, temperature, initial dye concentration, and pH) were investigated. Time to reach the equilibrium was dependent on dye concentration and it was 120 min for lower concentration and 240 min for higher concentration. The analysis of the kinetic data by pseudo-first-order and pseudo-second-order models displayed that MB adsorption followed pseudo-second-order model. The equilibrium data of MB adsorption were described by apply- ing the Langmuir, Freundlich, and Temkin models. The observations from adsorption isotherms indicated that Lang- muir model is the best fitted model and the maximum adsorption capacity (at the optimum pH 9.0) improved from 5.71 to 6.45 mg/g as the temperature increased from 298 to 328 K. The thermodynamic studies demonstrated that MB adsorption on to the adsorbent was spontaneous, feasible, and endothermic. Low desorption of the dyes from the adsor- bent indicates that the dyes might have been chemisorbed on to the adsorbent surface. A single-stage batch adsorber was designed and quantity of adsorbent required for treating 1– 10 L of stained water was determined based on the Lang- muir isotherm model equation. Results indicate that the com- posite bead could be an alternative for relatively costly adsorbents used for remediation of MB dye bearing industrial effluents
A pot culture experiment was conducted for two consecutive years in the late rainy season to eval... more A pot culture experiment was conducted for two consecutive years in the late rainy season to evaluate the efficiency of rock phosphate charged compost as an organic P fertilizer source in senna. A fixed dose of P (40 kg ha−1), considered optimum for quality produce was supplied from different sources like Di-ammonium phosphate (DAP), Single Super Phosphate (SSP), Rock phosphate (RP) and RP charged compost (RPCC). Fresh and dry weight of leaves and pods per plant were recorded while sennoside content in leaves and pods samples were analyzed. Total fresh and dry herbage yield (leaf+pod) was significantly higher under different P treatments than the control. Application of RP, SSP, DAP and RPCC increased fresh herbage yield up to 6.7, 22.6, 35.1 and 48.1%, respectively over the control. Sennoside content did not respond to all P sources, but appli- cation of RPCC improved sennoside content in herbage. The highest herbage yield and sennoside content was recorded under RPCC application. Available P and microbial biomass P in soil after harvesting of crop was significantly higher under RPCC application but on par with DAP application. Both acid and alkaline phos- phatase activities in soil were influenced by P sources, while alkaline phosphatase found significantly higher with RPCC application. So, it can be concluded from the study that enriched compost effectively supplement costly chemical fertilizer like DAP as a P source. The result from the study may be recommended for efficient P management in both commercial as well as organic cultivation of senna
A study was conducted to evaluate a waste rock powder collected from the Seaham quarry in New Sou... more A study was conducted to evaluate a waste rock powder collected from the Seaham quarry in New South Wales, Australia, as a source of potassium (K) in soil. The K supplying capacity of different size fractions of the mineral powder was evaluated by employing five chemical extractants as well as growing maize and holy basil in sand culture experiments. The K release by chemical extractants increased with decreasing particle size of the mineral powder. The amount of K released by different extractants followed the order: water<0.01M calcium chloride < 0.01 M citric acid < 1 N ammonium acetate < 1 N boiling nitric acid. The cumulative K release from the mineral powder in successive extraction procedure was recorded higher with organic and mineral acids, which suggested that the material was a slow release K source. A significant positive correlation was observed between K release by different chemical extractants and the biomass yield (r = 0.93; p < 0.05) and K uptake (r = 0.96; p < 0.05) by plants. Among the different chemical extractants, 1 N ammonium acetate and 1 N boiling HNO3 showed higher correlations (r = 0.91 and 0.96, respectively) with plant K uptake values. Both the chemical and biological methods were able to extract only a portion (12–20%) of total K present in the mineral powder. The results indicated that the mineral powder could be used as a slow release K fertilizer in soils. Further studies in long term applications with exhaustive crops under field conditions are needed to assess its feasibility as a source of K in agriculture
Journal of Material Cycles and Waste Management, 2018
An attempt was made to recycle waste biomass and mineral powder (waste mica) as an alternative so... more An attempt was made to recycle waste biomass and mineral powder (waste mica) as an alternative source of potassium (K) through composting technology. Two di erent waste biomass, isabgol straw and palmarosa distillation waste along with two levels of waste mica (2 and 4% as K) were used for preparation of enriched composts. A notable decrease of C:N ratio was observed at the end of the composting (150 days) as an indicator of compost maturity. The mature composts were evaluated for K-supplying capacity through laboratory leaching and soil incubation study. Signi cantly higher water-soluble K released initially followed by a sharp decrease up to 21 days of leaching thereafter gradually decreased up to 35 days of leaching. Water-soluble K was released from K-enriched (mica charged) compost signi cantly higher than the ordinary compost throughout the leaching period. Soil incubation study also revealed that application of K-enriched compost greatly improved the available K (water soluble and exchangeable) pools in K-de cient soil which indicated that a considerable amount of K releases during composting. Therefore, K-enriched compost could be an e ective alternative of costly commercial K fertilizer and eco-friendly approach to utilize low-cost waste mineral powder and plant residue.
Soil needs simultaneous replenishment of various nutrients to maintain its inherent fertility sta... more Soil needs simultaneous replenishment of various nutrients to maintain its inherent fertility status under extensive cropping systems. Replenishing soil nutrients with commercial fertilizer is costly. Among various fertilizers, deposits of potassium (K) ore suitable for the production of commercial K fertilizer (KCl) are distributed in few northern hemisphere countries (Canada, Russia, Belarus, and Germany) which control more than 70% of the world’s potash market. Naturally occurring minerals, particularly silicate minerals, could be used as a source of K, but not as satisfactorily as commercial K fertilizers. In this context, bio-intervention (in combination with microorganisms and/or composting) of silicate minerals has been found quite promising to improve plant K availability and assimilation. This is an energy efficient and environmentally friendly approach. Here we present a critical review of existing literature on direct application of silicate minerals as a source of K for plant nutrition as well as soil fertility enhancement by underpinning the bio-intervention strategies and related K solubilization mechanisms. An advancement of knowledge in this field will not only contribute to a better understanding of the complex natural processes of soil K fertility, but also help to develop a new approach to utilize natural mineral resources for sustainable and environmental friendly agricultural practices.
Proc. Natl. Acad. Sci., India, Sect. B Biol. Sci., 2017
Pot culture experiment was conducted in rabi season of 2012–2013 to evaluate the effect of micron... more Pot culture experiment was conducted in rabi season of 2012–2013 to evaluate the effect of micronutrients as zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) application on yield and quality of isabgol (Plantago ovata Forsk). Based on initial status of these micronutrients in soil different doses of each micronutrient were applied to isabgol under pot culture experiment. Biomass and seed yield of isabgol was improved significantly with the application of micronutrients. Quality parameters like test weight, isabgol husk percentage and swelling property of husk were found to improve with micronutrient application. Application of Zn, Cu, Fe and Mn increased isabgol husk yield up to 3.13, 2.11, 3.11 and 1.98 % respectively. Micronutrient treatment significantly increased their content and uptake by isabgol under pot culture experiment while soil micronutrient status was improved after harvesting of the crop. So it was found from the study that micronutrient application not only improved yield and quality of isabgol but also maintained the soil micronutrient status. The micronutrient fertilizers supply particular micronutrient to the soil available pool of micronutrient which helps in maintaining micronutrient status in soil for next crop.
In this study, value added compost was prepared from low-grade Indian rock phosphates (RPs) and i... more In this study, value added compost was prepared from low-grade Indian rock phosphates (RPs) and isabgol straw as an alternative sources of phosphorus. Three different sources of low-grade RP namely Udaipur, Jhabua and Purulia were evaluated for alternative source of P. Total carbon (C) decreased while total nitrogen (N) increased, leading to a decrease in the C/N ratio at the end of composting. Notable increases in total and available P was found in the composts charged with RPs. The rate of P released from the composts was studied through leaching experiment in the laboratory. An incubation study was carried out to evaluate the effect of different compost on soil P availability. Data revealed that the sharp increase in water soluble P from all the compost at 14 days of leaching then a gradual decrease. Significantly higher water soluble P released from the value added (RP charged) compost as compared to ordinary compost throughout the leaching period. Application of value added compost in soil increased water soluble, available P, microbial biomass C and P as well as acid and alkaline phosphatase activity in soil. Initially, the value added compost showed lower available P as compared to DAP however, improved significantly at a later stage of incubation. The increase in different labile pools of P in soil amended with value added compost also indicates substantial amount of P mobilized from the compost during incubation. Thus, the value added compost could be an effective alternative of chemical fertilizer and promising technology to utilize low-grade RP as P source.
A field experiment was conducted to study the dissipation kinetics of herbicides pendimethalin an... more A field experiment was conducted to study the dissipation kinetics of herbicides pendimethalin and oxyfluorfen in black soil of peanut field at half recommended rate (HRE), recommended rate and double recommended rate as well as to assess their effects on soil microbial parameters and enzymatic activities. In addition, their role in the transformations and availability of some plant nutrients like nitrogen transformation (through ammonification and nitrification processes) and availability of phosphorous were also studied. Incorporation of these herbicides was found to stimulate the activity of soil microbial biomass carbon, fluorescein diacetate hydrolysing activity, alkaline phosphatase and ammonification rates, while dehydrogenase activity, acid phosphatase, nitrification rate and available phosphorous was adversely affected. However, urease remains almost unchanged except for little stimulation at later stages. Dis-sipation of pendimethalin and oxyfluorfen followed first-order reaction kinetics with half-life (T 1/2) of 13.7–20.1 and 21.5–27.4 days, respectively. Residues of both herbicides persisted up to 60 days in the soil at all the doses except 45 days for pendimethalin at HRE.
A B S T R A C T With the increasing popularity and use of medicinal herbs, their global demand ha... more A B S T R A C T With the increasing popularity and use of medicinal herbs, their global demand has gained momentum. Developing countries, including China, India and South East Asian (SEA) countries, are the centres of origin and major global suppliers for most of these traditionally used medicinal herbs. One of the factors affecting the quality of these herbs is the contamination of heavy metals, mycotoxins, pesticide residues, polycyclic aromatic hydrocarbons (PAHs) and fumigants. These contaminants can accumulate during the cultivation, storage and processing of herbs and may have adverse effects on consumer health. There have been various reports regarding the presence of these contaminants in medicinal herbs. This review discusses the important contaminants of medicinal herbs, the frequency and magnitude of their occurrences, the potential causes of contamination and their regulatory limits in medicinal herbs. The major challenge in the international trade of medicinal herbs is the lack of common guidelines, regulatory measures and monitoring body to strictly enforce their regulation.
Most of the Indian rock phosphates (RPs) are not suitable for production of commercial phosphate ... more Most of the Indian rock phosphates (RPs) are not suitable for production of commercial phosphate fertilizer because of their low phosphorus (P) content (low-grade). They are suitable as source of P in acid soil, but not effective for direct use in neutral to alkaline soil. The main aim of this study was to evaluate the potentiality of these RPs as liming material and subsequently their effect on P availability in acid soil. Four Indian RPs namely, Udaipur, Mussoorie, Jhabua and Purulia were evaluated for their liming potential through theoretical calculations, laboratory titration and soil incubation studies. The incubation experiment was carried out for 90 days to quantify more accurate per cent calcium carbonate equivalence (%CCE) values of RPs as well as the changes in pH, exchangeable aluminum (Al) and P availability in an acid soil having pH 4.53. Results emanated from the theoretical calculation showed that the %CCE of Indian RPs varied from 59 to 62. While, laboratory studies on quantification of %CCE (AOAC method 955.01) of RPs by titration ranged between 39.9 and 53.7 which were lesser than the theoretical values. The %CCE values obtained in soil incubation study at lower rate of RP application followed the similar pattern as those values obtained in the theoretical calculation. Though RP was less effective in increasing soil pH as compared to CaCO 3 , there was an increase in soil pH due to application of RPs, which is sufficient enough to decrease the content of Al much below the toxic and safe limit for supplying available P for plant growth. Thus, application of low-grade RPs could be a potential option as liming material in acid soil in addition to a source of P for crop production.
Potassium (K) is the third major essential plant nutrient and plays an essential role for enzyme ... more Potassium (K) is the third major essential plant nutrient and plays an essential role for enzyme activation, protein synthesis and photosynthesis and quality of produce. It is a major constituent of several soil minerals and quite abundant in many soils, particularly in India. However, the soil K levels have dropped in many soils due to continuous mining of it through crop removal without replenishing it. In India, the cost of K-fertilisers is very high because there is no reserve of K-bearing minerals for manufacturing of conventional K-fertilisers and the whole consumption is imported, costing huge amount of foreign exchange. In this context, it is important to see the microbial solubilisation of K-bearing minerals in soils and their potentiality as K-fertiliser in sustainable crop production and in maintaining K status in soils. In this article, we reviewed the potential sources of K-bearing minerals in soil and their efficient utilization as source of K to plants by microbial activation. The primary sources of K-bearing minerals in soils are feldspars, micas, zeolite, glauconite, illite, vermiculite and chlorite. Different strains of potassium solubilising microorganisms and their diverse mechanisms in enhancing K availability in soil are discussed. It is demonstrated that microbes can accelerate weathering reactions of K-minerals, especially when in direct contact with mineral surfaces either by production of organic acids; formation of biofilms; mobilisation by plant growth promoting rhizobacteria; and mobilisation by mycorrhizal fungi. Attempts have been made to use of potassium mobilizing microbes for solubilising potassium from K-bearing minerals and hence to improve plant nutrition. The present review demonstrated that bio-intervention of potassium solubilising microorganisms to naturally available K-bearing minerals could be an alternative and viable technology to solubilise insoluble K into soluble form which could be used efficiently as a source of K-fertiliser for sustaining crop production and maintaining soil potassium. Advancement of the knowledge in this field will not only contribute to a better understanding of complex natural processes, but also will help to develop new industrial applications, as well as sustainable and environmental friendly practices in agriculture.
The main aim of this study was to quantify the C and N mineralization rates in soil from organic ... more The main aim of this study was to quantify the C and N mineralization rates in soil from organic and inorganic fertilizers as affected by temperature and moisture regimes. Laboratory incubation experiment was carried out with eight treatments consisting of combinations of value-added organic manures namely, vermicompost, NADEP compost, FYM and inorganic fertilizers. Soil (40 g) was mixed thoroughly with required quantities of organic manures and chemical fertilizers and placed in 500 mL hermetically sealed flasks and incubated at two temperatures viz., 20 and 35 o C and two soil moisture regimes viz., 0.33 bar (field capacity) and 1.0 bar for 7, 15, 30, 60 and 90 days. Destructive samplings were done and C mineralization and mineral N were determined at each interval. Data emanated were fitted to first-order exponential equation to predict the potential mineralizable C (C O) and N (N O) as well as mineralization constants (k C and k N). Results indicated that highest values of C mineralization and mineral N were associated with treatment containing value-added organic manures in combination with fertilizers. Across the incubation periods and treatments, around 15.4% increase in C mineralization was observed due to increase in temperature from 20 to 35 o C while 73.3% increase was observed as the soil moisture regime shifted from 1.0 bar to field capacity. Similarly, around 5.7% increase in mineral N was recorded due to increase in temperature from 20 to 35 o C while 10.2% increase was observed as the soil moisture regime shifted from 1.0 bar to field capacity. Data on C and N mineralization were well fitted to exponential equation as evidenced from their correlation coefficients (R 2) values. Potential mineralizable C and N as well as mineralization constants were significantly influenced by the application of organic manures in combination with fertilizers.
The effect of three value-added manures viz., vermicompost, NADEP compost and FYM was evaluated f... more The effect of three value-added manures viz., vermicompost, NADEP compost and FYM was evaluated for crop production and maintaining soil mineral N and organic C pools in an Inceptisol under a maize-wheat cropping system. Vermicompost was prepared from various farm wastes using Eisenia foetida and cattle dung (5%, w/w). NADEP compost was prepared using mixed crop residues like maize, oat, berseem, jowar, lobia and seasonal grasses and cattle dung (2%, w/w) in pit, while FYM was prepared by trench method using cattle dung. Data revealed that yield and N uptake by maize and wheat due to conjoint use of value-added manures and chemical fertilizers increased significantly over application of value-added manures alone. Mineral N and microbial biomass N (MBN) in soil improved significantly with application of 100% NPK than plots receiving organic manures alone as well as integrated use of manures and 50% NPK. Plots amended with value-added manures maintained higher soil organic carbon (SOC) pools viz., Walkley Black C (WBC), KMnO 4-oxidizable labile C (LBC), microbial biomass C (MBC) and mineralizable C (C min) over control. The effect in improving SOC pools further enhanced in plots amended with conjoint use of value-added manure (5 Mg ha-1) and 50% NPK fertilizers than plots amended with value-added manure alone. Pearson's correlation matrix showed significant and positive relationships between yield, N uptake by crops with soil mineral N, MBN and pools of SOC. The results demonstrated that integrated use of value-added manures along with 50% NPK fertilizers could maintain higher mineral N and SOC pools, which may be considered as a feasible and environment-friendly option for recycling various farm wastes including crop residues and cattle dung into a value-added product, thereby effecting a 50% saving on costly chemical fertilizers.
field experiment was conducted in a Typic Haplustept of semiarid
sub-tropical India to evaluate t... more field experiment was conducted in a Typic Haplustept of semiarid sub-tropical India to evaluate the effect of value added manures and fertilizers on soil health, grain quality and enzyme activities under maize-wheat rotation. Eight treatments consisting of three organic manures (vermicompost, NADEP compost and farm yard manure) and fertilizers in different combinations were applied. The highest dehydrogenase activity (18.87 and 17.97 μg triphenylformazan g-1 soil h-1 in maize and wheat, respectively) was reflected under integrated application of organic and fertilizers, whereas the highest urease activity (7.76 and 9.43 μg urea g-1 h-1 in maize and wheat,respectively) was observed in 100% NPK. Application of 50% NPK along with organic manures significantly improved grain yield and mineral composition. Grain protein content and weight of maize and wheat were higher under integrated nutrient management and 100% NPK. Microbial biomass carbon and nitrogen were significantly influenced by various nutrient management practices during different physiological stages of crop growth.
– An attempt was made to mobilize potassium (K) from a K-bearing mineral (waste mica) inoculated ... more – An attempt was made to mobilize potassium (K) from a K-bearing mineral (waste mica) inoculated with K-solubilizing bacteria (Bacillus mucilaginosus) as a function of temperature and incubation period under in vitro laboratory conditions. A series of incubation experiments were carried out to study the mobilization of K from waste mica. Destructive samplings were drawn at different periods of incubation and analyzed for pH, total sugar content and NH 4 OAc-K. The results showed that irrespective of temperature and period of incubation, a significantly higher mobilization of K was recorded in all the treatments when incubation was carried out in the presence of the bacterial strain compared to control. The pH and total sugar content were found to decrease in the presence of Bacillus mucilaginosus as compared to control, while in the presence of the bacterial strain the NH 4 OAc-K content increased from 12.3 to 46.0%, irrespective of treatments. Thus, it may be concluded that waste mica inoculated with a K-solubilizing strain could be a promising technology to utilize waste mica, and could be used effectively as an alternative source of K-fertilizer for crop production.
Sacred basil / Holy basil (Ocimum sanctum Linn) is a sacred plant widely used in pharmaceutical /... more Sacred basil / Holy basil (Ocimum sanctum Linn) is a sacred plant widely used in pharmaceutical / cosmetic industries and is known for its varied medicinal properties. In order to study the influence of organic sources of nutrients on growth, yield and quality of sacred basil (Purple type), a field experiment was conducted at the ICAR-Directorate of Medicinal and Aromatic Plants Research, Boriavi, Anand, Gujarat for two consecutive seasons during 2015-2016. The experiment was devised in split plot design with three main plots (no organic/ fallow, green manuring with cowpea (Vigna unguiculata (L.) Walp.) and crop residue of cluster bean (Cyamopsis tetragonoloba L. Taub) and seven sub plots (Control / no FYM (Farm yard manure), 50% N equivalent through FYM, 75% N equivalent through FYM, 100% N equivalent through FYM, 50% N equivalent through FYM + Arka Microbial consortia (AMC), 75% N equivalent through FYM + AMC and 100% N equivalent through FYM + AMC) in three replications. Results revealed that different plant growth parameters with respect to plant height, plant spread and number of branches and yield parameters such as dry herb yield, and essential oil content of pooled mean of two harvests (5.03 t ha −1 , 1.35% and 6.79 kg ha −1 , respectively) were recorded maximum in the treatment which received cluster bean crop residue. Among sub plot treatments, application of 100% N equivalent through FYM + AMC (N fixing, P & Zn solubilising and plant growth promoting microbes) recorded maximum dry herb yield (6.30 t ha −1), essential oil content (1.71%) and essential oil yield (10.79 kg ha −1) for the pooled mean of two harvests. Application of different crop residues significantly improved organic carbon (SOC) and available nutrient contents in soil, improved available nitrogen, phosphorus and potassium contents, soil microbial biomass (MBC) and dehydrogenase activity (DHA) compared with control. With these results, it can be concluded that incorporation of cluster bean crop residue prior to transplanting and application of 100% N equivalent through FYM + Arka microbial consortia could be recommended as organic production technology in sacred basil to obtain higher herbage yield and quality.
Cultivation of medicinal plants by maintaining sustainable environment with low chemical inputs i... more Cultivation of medicinal plants by maintaining sustainable environment with low chemical inputs is attempted through a pot culture experiment by integrating the biochar prepared from lemongrass (Cymbopogon flexuosus) distillation waste and chemical fertilizers (CF) in different ratios. The objective was to find out the influence on yield, physiology and quality of Andrographis paniculata (kalmegh) herb and on soil chemical/biological properties. All the growth parameters and yield were significantly influenced by the integrated biochar and CF application. Biochar application, remarkably improved the soil carbon content, cation exchange capacity and nutrients accessibility. However, significantly higher fresh herbage yield (140.8 g plant −1) was recorded in the treatment receiving biochar (5 t ha −1) combined with recommended dose of CF (60:20:40 NPK kg ha −1). The same treatment resulted in higher soil microbial biomass C, fluorescein diacetate hydrolytic, dehydrogenase and alkaline phosphatase activity. Total phenol/flavonoid contents and antioxidant (DPPH and ABTS) activities, were higher in sole biochar treated plant and increased further in combination with CF. Sole application of biochar or CF did not have any significant influence on leaf andrographolide content, however their combination increased the content but the effects were not significant on stem andrographolide. The reduction in stomatal conductance and higher water use efficiency after biochar application indicates it's potential to mitigate water deficit stress. Results indicate that use of only biochar was not enough to improve the plant growth and soil health. Therefore, to achieve environmentally safe and quality herb production, it is recommended to use combination of biochar and CF which not only improve crop yield and quality but also improves the soil quality.
The potassium supplying capacity of the waste mica powder (WMP) was evaluated through chemical an... more The potassium supplying capacity of the waste mica powder (WMP) was evaluated through chemical and biological means. Four different size fractions of the WMP were studied in laboratory by different chemical extractants. At the same time, experiment of the plant growth was conducted in pot using K-deficient soil. The K release from the WMP by dif- ferent extractants followed an increasing trend with an increase in the fineness of the par- ticles. The highest K release was recorded by boiling 1 M HNO3 (376.4–1726.4 mg kg 1) followed by 1 M ammonium acetate (33.5–226.5 mg kg 1), 0.01 M citric acid (31.6– 158.3 mg kg 1) and water (12.0–112.0 mg kg 1) irrespective of the various size fractions. Significantly, higher cumulative K release from the WMP in successive extraction was re- corded with 1 M boiling HNO3 that predicts its slow-release property. The K release by different extractants was correlated significantly and positively with the biomass yield and K uptake by plants. 1 M boiling HNO3 extractable K showed higher correlation values with the biomass yield and K uptake. Therefore, it suggests that the extractant might be a better indicator of K supplying capacity of the WMP. The plant intervention was able to extract 32.8% of total K from the WMP simultaneously improving the exchangeable and non- exchangeable K pool in soil. These above-mentioned results conclude that plants can get access to a significant amount of K from the WMP and it could be an effective source of K in highly weathered tropical soils under K deficiency.
Low molecular weight organic acids (LMWOAs) are naturally occurred in soil, particularly in the r... more Low molecular weight organic acids (LMWOAs) are naturally occurred in soil, particularly in the rhizosphere due to microbial metabolites and secretion of root exudates. Various functional groups present in LMWOAs can play an effective role in phosphorus dissolution. In this study, potentiality of LMWOAs for phosphorous release from low-grade Indian rock phosphates (RPs) collected from Udaipur, Jhabua and Purulia was investigated under laboratory conditions. The characteristic of P release and the factors influencing P release from selected low-grade RPs by using seven LMWOAs along with two inorganic acids were also investigated. The amount of P release from RPs with di erent acids at various concentrations and equilibrium pH as well as the di erent factors of P release was also compared. Results showed that the average amounts of P released by all the organic acids from the three RPs increased with the concentration of organic acids. The amount of P release by the organic acids from the RPs followed the order, i.e. oxalic acid > citric acid > tartaric acid > formic acid > malic acid > succinic acid > acetic acid. A negative correlation was observed between P released from RPs and an equilibrium solution pH. The average amounts P released from all sources of RP ranged from 12 to 81 mmol P kg−1 by acetic acid and citric acid respectively. In addition, the nature of RPs, RP/acid solution ratio, leaching time and temperature significantly influenced the P release from RPs by organic acids. Thus, the LMWOAs could be a potential amendment for improving bio availability of P from RP.
The chemical reactivity of Indian rock phosphates (RPs) was measured by five chemical extraction ... more The chemical reactivity of Indian rock phosphates (RPs) was measured by five chemical extraction methods (i.e. water, neutral ammonium citrate (NCA), 2% citric acid (CA), 2% formic acid (FA) and absolute citrate solubility (ACS)). These measurements were assessed by agronomic response data obtained by growing ryegrass and palmarosa in two highly weathered acidic soils under pot culture experiment. The phosphorus (P) solubility value of RP measured by different methods followed the order: ACS > 2% CA > 2% FA > NAC > water. Considering triple superphosphate (TSP) as a standard reference P fertilizer, the agronomic response of RPs followed the order Udaipur RP > Jhabua RP ≥ Purulia RP > Mussorie RP. Methods based on citrate solubility (i.e. NAC, 2% CA and ACS) were significantly and positively correlated with agronomic response irrespective of the plant species and soil types. The best correlation value obtained with NCA indicated that P solubility in NAC solution may offer better prediction of agronomic effectiveness of RP in terms of biomass yield, relative agronomic efficiency (RAE) and P recovery efficiency. So, the present investigation will help to predict the agronomic effectiveness of low-grade RP based on chemical methods.
This study described a preparation of a low-cost adsorbent by entrapment of palmarosa distillatio... more This study described a preparation of a low-cost adsorbent by entrapment of palmarosa distillation wastes into alginate as supporting matrix and use of it for methylene blue (MB) dye removal from aqueous solution. Fourier transform infra- red spectroscopy (FTIR) data of adsorbent confirms the entrapment for formation of composite beads. The effects of adsorption parameters (adsorbent dose, temperature, initial dye concentration, and pH) were investigated. Time to reach the equilibrium was dependent on dye concentration and it was 120 min for lower concentration and 240 min for higher concentration. The analysis of the kinetic data by pseudo-first-order and pseudo-second-order models displayed that MB adsorption followed pseudo-second-order model. The equilibrium data of MB adsorption were described by apply- ing the Langmuir, Freundlich, and Temkin models. The observations from adsorption isotherms indicated that Lang- muir model is the best fitted model and the maximum adsorption capacity (at the optimum pH 9.0) improved from 5.71 to 6.45 mg/g as the temperature increased from 298 to 328 K. The thermodynamic studies demonstrated that MB adsorption on to the adsorbent was spontaneous, feasible, and endothermic. Low desorption of the dyes from the adsor- bent indicates that the dyes might have been chemisorbed on to the adsorbent surface. A single-stage batch adsorber was designed and quantity of adsorbent required for treating 1– 10 L of stained water was determined based on the Lang- muir isotherm model equation. Results indicate that the com- posite bead could be an alternative for relatively costly adsorbents used for remediation of MB dye bearing industrial effluents
A pot culture experiment was conducted for two consecutive years in the late rainy season to eval... more A pot culture experiment was conducted for two consecutive years in the late rainy season to evaluate the efficiency of rock phosphate charged compost as an organic P fertilizer source in senna. A fixed dose of P (40 kg ha−1), considered optimum for quality produce was supplied from different sources like Di-ammonium phosphate (DAP), Single Super Phosphate (SSP), Rock phosphate (RP) and RP charged compost (RPCC). Fresh and dry weight of leaves and pods per plant were recorded while sennoside content in leaves and pods samples were analyzed. Total fresh and dry herbage yield (leaf+pod) was significantly higher under different P treatments than the control. Application of RP, SSP, DAP and RPCC increased fresh herbage yield up to 6.7, 22.6, 35.1 and 48.1%, respectively over the control. Sennoside content did not respond to all P sources, but appli- cation of RPCC improved sennoside content in herbage. The highest herbage yield and sennoside content was recorded under RPCC application. Available P and microbial biomass P in soil after harvesting of crop was significantly higher under RPCC application but on par with DAP application. Both acid and alkaline phos- phatase activities in soil were influenced by P sources, while alkaline phosphatase found significantly higher with RPCC application. So, it can be concluded from the study that enriched compost effectively supplement costly chemical fertilizer like DAP as a P source. The result from the study may be recommended for efficient P management in both commercial as well as organic cultivation of senna
A study was conducted to evaluate a waste rock powder collected from the Seaham quarry in New Sou... more A study was conducted to evaluate a waste rock powder collected from the Seaham quarry in New South Wales, Australia, as a source of potassium (K) in soil. The K supplying capacity of different size fractions of the mineral powder was evaluated by employing five chemical extractants as well as growing maize and holy basil in sand culture experiments. The K release by chemical extractants increased with decreasing particle size of the mineral powder. The amount of K released by different extractants followed the order: water<0.01M calcium chloride < 0.01 M citric acid < 1 N ammonium acetate < 1 N boiling nitric acid. The cumulative K release from the mineral powder in successive extraction procedure was recorded higher with organic and mineral acids, which suggested that the material was a slow release K source. A significant positive correlation was observed between K release by different chemical extractants and the biomass yield (r = 0.93; p < 0.05) and K uptake (r = 0.96; p < 0.05) by plants. Among the different chemical extractants, 1 N ammonium acetate and 1 N boiling HNO3 showed higher correlations (r = 0.91 and 0.96, respectively) with plant K uptake values. Both the chemical and biological methods were able to extract only a portion (12–20%) of total K present in the mineral powder. The results indicated that the mineral powder could be used as a slow release K fertilizer in soils. Further studies in long term applications with exhaustive crops under field conditions are needed to assess its feasibility as a source of K in agriculture
Journal of Material Cycles and Waste Management, 2018
An attempt was made to recycle waste biomass and mineral powder (waste mica) as an alternative so... more An attempt was made to recycle waste biomass and mineral powder (waste mica) as an alternative source of potassium (K) through composting technology. Two di erent waste biomass, isabgol straw and palmarosa distillation waste along with two levels of waste mica (2 and 4% as K) were used for preparation of enriched composts. A notable decrease of C:N ratio was observed at the end of the composting (150 days) as an indicator of compost maturity. The mature composts were evaluated for K-supplying capacity through laboratory leaching and soil incubation study. Signi cantly higher water-soluble K released initially followed by a sharp decrease up to 21 days of leaching thereafter gradually decreased up to 35 days of leaching. Water-soluble K was released from K-enriched (mica charged) compost signi cantly higher than the ordinary compost throughout the leaching period. Soil incubation study also revealed that application of K-enriched compost greatly improved the available K (water soluble and exchangeable) pools in K-de cient soil which indicated that a considerable amount of K releases during composting. Therefore, K-enriched compost could be an e ective alternative of costly commercial K fertilizer and eco-friendly approach to utilize low-cost waste mineral powder and plant residue.
Soil needs simultaneous replenishment of various nutrients to maintain its inherent fertility sta... more Soil needs simultaneous replenishment of various nutrients to maintain its inherent fertility status under extensive cropping systems. Replenishing soil nutrients with commercial fertilizer is costly. Among various fertilizers, deposits of potassium (K) ore suitable for the production of commercial K fertilizer (KCl) are distributed in few northern hemisphere countries (Canada, Russia, Belarus, and Germany) which control more than 70% of the world’s potash market. Naturally occurring minerals, particularly silicate minerals, could be used as a source of K, but not as satisfactorily as commercial K fertilizers. In this context, bio-intervention (in combination with microorganisms and/or composting) of silicate minerals has been found quite promising to improve plant K availability and assimilation. This is an energy efficient and environmentally friendly approach. Here we present a critical review of existing literature on direct application of silicate minerals as a source of K for plant nutrition as well as soil fertility enhancement by underpinning the bio-intervention strategies and related K solubilization mechanisms. An advancement of knowledge in this field will not only contribute to a better understanding of the complex natural processes of soil K fertility, but also help to develop a new approach to utilize natural mineral resources for sustainable and environmental friendly agricultural practices.
Proc. Natl. Acad. Sci., India, Sect. B Biol. Sci., 2017
Pot culture experiment was conducted in rabi season of 2012–2013 to evaluate the effect of micron... more Pot culture experiment was conducted in rabi season of 2012–2013 to evaluate the effect of micronutrients as zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) application on yield and quality of isabgol (Plantago ovata Forsk). Based on initial status of these micronutrients in soil different doses of each micronutrient were applied to isabgol under pot culture experiment. Biomass and seed yield of isabgol was improved significantly with the application of micronutrients. Quality parameters like test weight, isabgol husk percentage and swelling property of husk were found to improve with micronutrient application. Application of Zn, Cu, Fe and Mn increased isabgol husk yield up to 3.13, 2.11, 3.11 and 1.98 % respectively. Micronutrient treatment significantly increased their content and uptake by isabgol under pot culture experiment while soil micronutrient status was improved after harvesting of the crop. So it was found from the study that micronutrient application not only improved yield and quality of isabgol but also maintained the soil micronutrient status. The micronutrient fertilizers supply particular micronutrient to the soil available pool of micronutrient which helps in maintaining micronutrient status in soil for next crop.
In this study, value added compost was prepared from low-grade Indian rock phosphates (RPs) and i... more In this study, value added compost was prepared from low-grade Indian rock phosphates (RPs) and isabgol straw as an alternative sources of phosphorus. Three different sources of low-grade RP namely Udaipur, Jhabua and Purulia were evaluated for alternative source of P. Total carbon (C) decreased while total nitrogen (N) increased, leading to a decrease in the C/N ratio at the end of composting. Notable increases in total and available P was found in the composts charged with RPs. The rate of P released from the composts was studied through leaching experiment in the laboratory. An incubation study was carried out to evaluate the effect of different compost on soil P availability. Data revealed that the sharp increase in water soluble P from all the compost at 14 days of leaching then a gradual decrease. Significantly higher water soluble P released from the value added (RP charged) compost as compared to ordinary compost throughout the leaching period. Application of value added compost in soil increased water soluble, available P, microbial biomass C and P as well as acid and alkaline phosphatase activity in soil. Initially, the value added compost showed lower available P as compared to DAP however, improved significantly at a later stage of incubation. The increase in different labile pools of P in soil amended with value added compost also indicates substantial amount of P mobilized from the compost during incubation. Thus, the value added compost could be an effective alternative of chemical fertilizer and promising technology to utilize low-grade RP as P source.
A field experiment was conducted to study the dissipation kinetics of herbicides pendimethalin an... more A field experiment was conducted to study the dissipation kinetics of herbicides pendimethalin and oxyfluorfen in black soil of peanut field at half recommended rate (HRE), recommended rate and double recommended rate as well as to assess their effects on soil microbial parameters and enzymatic activities. In addition, their role in the transformations and availability of some plant nutrients like nitrogen transformation (through ammonification and nitrification processes) and availability of phosphorous were also studied. Incorporation of these herbicides was found to stimulate the activity of soil microbial biomass carbon, fluorescein diacetate hydrolysing activity, alkaline phosphatase and ammonification rates, while dehydrogenase activity, acid phosphatase, nitrification rate and available phosphorous was adversely affected. However, urease remains almost unchanged except for little stimulation at later stages. Dis-sipation of pendimethalin and oxyfluorfen followed first-order reaction kinetics with half-life (T 1/2) of 13.7–20.1 and 21.5–27.4 days, respectively. Residues of both herbicides persisted up to 60 days in the soil at all the doses except 45 days for pendimethalin at HRE.
A B S T R A C T With the increasing popularity and use of medicinal herbs, their global demand ha... more A B S T R A C T With the increasing popularity and use of medicinal herbs, their global demand has gained momentum. Developing countries, including China, India and South East Asian (SEA) countries, are the centres of origin and major global suppliers for most of these traditionally used medicinal herbs. One of the factors affecting the quality of these herbs is the contamination of heavy metals, mycotoxins, pesticide residues, polycyclic aromatic hydrocarbons (PAHs) and fumigants. These contaminants can accumulate during the cultivation, storage and processing of herbs and may have adverse effects on consumer health. There have been various reports regarding the presence of these contaminants in medicinal herbs. This review discusses the important contaminants of medicinal herbs, the frequency and magnitude of their occurrences, the potential causes of contamination and their regulatory limits in medicinal herbs. The major challenge in the international trade of medicinal herbs is the lack of common guidelines, regulatory measures and monitoring body to strictly enforce their regulation.
Most of the Indian rock phosphates (RPs) are not suitable for production of commercial phosphate ... more Most of the Indian rock phosphates (RPs) are not suitable for production of commercial phosphate fertilizer because of their low phosphorus (P) content (low-grade). They are suitable as source of P in acid soil, but not effective for direct use in neutral to alkaline soil. The main aim of this study was to evaluate the potentiality of these RPs as liming material and subsequently their effect on P availability in acid soil. Four Indian RPs namely, Udaipur, Mussoorie, Jhabua and Purulia were evaluated for their liming potential through theoretical calculations, laboratory titration and soil incubation studies. The incubation experiment was carried out for 90 days to quantify more accurate per cent calcium carbonate equivalence (%CCE) values of RPs as well as the changes in pH, exchangeable aluminum (Al) and P availability in an acid soil having pH 4.53. Results emanated from the theoretical calculation showed that the %CCE of Indian RPs varied from 59 to 62. While, laboratory studies on quantification of %CCE (AOAC method 955.01) of RPs by titration ranged between 39.9 and 53.7 which were lesser than the theoretical values. The %CCE values obtained in soil incubation study at lower rate of RP application followed the similar pattern as those values obtained in the theoretical calculation. Though RP was less effective in increasing soil pH as compared to CaCO 3 , there was an increase in soil pH due to application of RPs, which is sufficient enough to decrease the content of Al much below the toxic and safe limit for supplying available P for plant growth. Thus, application of low-grade RPs could be a potential option as liming material in acid soil in addition to a source of P for crop production.
Potassium (K) is the third major essential plant nutrient and plays an essential role for enzyme ... more Potassium (K) is the third major essential plant nutrient and plays an essential role for enzyme activation, protein synthesis and photosynthesis and quality of produce. It is a major constituent of several soil minerals and quite abundant in many soils, particularly in India. However, the soil K levels have dropped in many soils due to continuous mining of it through crop removal without replenishing it. In India, the cost of K-fertilisers is very high because there is no reserve of K-bearing minerals for manufacturing of conventional K-fertilisers and the whole consumption is imported, costing huge amount of foreign exchange. In this context, it is important to see the microbial solubilisation of K-bearing minerals in soils and their potentiality as K-fertiliser in sustainable crop production and in maintaining K status in soils. In this article, we reviewed the potential sources of K-bearing minerals in soil and their efficient utilization as source of K to plants by microbial activation. The primary sources of K-bearing minerals in soils are feldspars, micas, zeolite, glauconite, illite, vermiculite and chlorite. Different strains of potassium solubilising microorganisms and their diverse mechanisms in enhancing K availability in soil are discussed. It is demonstrated that microbes can accelerate weathering reactions of K-minerals, especially when in direct contact with mineral surfaces either by production of organic acids; formation of biofilms; mobilisation by plant growth promoting rhizobacteria; and mobilisation by mycorrhizal fungi. Attempts have been made to use of potassium mobilizing microbes for solubilising potassium from K-bearing minerals and hence to improve plant nutrition. The present review demonstrated that bio-intervention of potassium solubilising microorganisms to naturally available K-bearing minerals could be an alternative and viable technology to solubilise insoluble K into soluble form which could be used efficiently as a source of K-fertiliser for sustaining crop production and maintaining soil potassium. Advancement of the knowledge in this field will not only contribute to a better understanding of complex natural processes, but also will help to develop new industrial applications, as well as sustainable and environmental friendly practices in agriculture.
The main aim of this study was to quantify the C and N mineralization rates in soil from organic ... more The main aim of this study was to quantify the C and N mineralization rates in soil from organic and inorganic fertilizers as affected by temperature and moisture regimes. Laboratory incubation experiment was carried out with eight treatments consisting of combinations of value-added organic manures namely, vermicompost, NADEP compost, FYM and inorganic fertilizers. Soil (40 g) was mixed thoroughly with required quantities of organic manures and chemical fertilizers and placed in 500 mL hermetically sealed flasks and incubated at two temperatures viz., 20 and 35 o C and two soil moisture regimes viz., 0.33 bar (field capacity) and 1.0 bar for 7, 15, 30, 60 and 90 days. Destructive samplings were done and C mineralization and mineral N were determined at each interval. Data emanated were fitted to first-order exponential equation to predict the potential mineralizable C (C O) and N (N O) as well as mineralization constants (k C and k N). Results indicated that highest values of C mineralization and mineral N were associated with treatment containing value-added organic manures in combination with fertilizers. Across the incubation periods and treatments, around 15.4% increase in C mineralization was observed due to increase in temperature from 20 to 35 o C while 73.3% increase was observed as the soil moisture regime shifted from 1.0 bar to field capacity. Similarly, around 5.7% increase in mineral N was recorded due to increase in temperature from 20 to 35 o C while 10.2% increase was observed as the soil moisture regime shifted from 1.0 bar to field capacity. Data on C and N mineralization were well fitted to exponential equation as evidenced from their correlation coefficients (R 2) values. Potential mineralizable C and N as well as mineralization constants were significantly influenced by the application of organic manures in combination with fertilizers.
The effect of three value-added manures viz., vermicompost, NADEP compost and FYM was evaluated f... more The effect of three value-added manures viz., vermicompost, NADEP compost and FYM was evaluated for crop production and maintaining soil mineral N and organic C pools in an Inceptisol under a maize-wheat cropping system. Vermicompost was prepared from various farm wastes using Eisenia foetida and cattle dung (5%, w/w). NADEP compost was prepared using mixed crop residues like maize, oat, berseem, jowar, lobia and seasonal grasses and cattle dung (2%, w/w) in pit, while FYM was prepared by trench method using cattle dung. Data revealed that yield and N uptake by maize and wheat due to conjoint use of value-added manures and chemical fertilizers increased significantly over application of value-added manures alone. Mineral N and microbial biomass N (MBN) in soil improved significantly with application of 100% NPK than plots receiving organic manures alone as well as integrated use of manures and 50% NPK. Plots amended with value-added manures maintained higher soil organic carbon (SOC) pools viz., Walkley Black C (WBC), KMnO 4-oxidizable labile C (LBC), microbial biomass C (MBC) and mineralizable C (C min) over control. The effect in improving SOC pools further enhanced in plots amended with conjoint use of value-added manure (5 Mg ha-1) and 50% NPK fertilizers than plots amended with value-added manure alone. Pearson's correlation matrix showed significant and positive relationships between yield, N uptake by crops with soil mineral N, MBN and pools of SOC. The results demonstrated that integrated use of value-added manures along with 50% NPK fertilizers could maintain higher mineral N and SOC pools, which may be considered as a feasible and environment-friendly option for recycling various farm wastes including crop residues and cattle dung into a value-added product, thereby effecting a 50% saving on costly chemical fertilizers.
field experiment was conducted in a Typic Haplustept of semiarid
sub-tropical India to evaluate t... more field experiment was conducted in a Typic Haplustept of semiarid sub-tropical India to evaluate the effect of value added manures and fertilizers on soil health, grain quality and enzyme activities under maize-wheat rotation. Eight treatments consisting of three organic manures (vermicompost, NADEP compost and farm yard manure) and fertilizers in different combinations were applied. The highest dehydrogenase activity (18.87 and 17.97 μg triphenylformazan g-1 soil h-1 in maize and wheat, respectively) was reflected under integrated application of organic and fertilizers, whereas the highest urease activity (7.76 and 9.43 μg urea g-1 h-1 in maize and wheat,respectively) was observed in 100% NPK. Application of 50% NPK along with organic manures significantly improved grain yield and mineral composition. Grain protein content and weight of maize and wheat were higher under integrated nutrient management and 100% NPK. Microbial biomass carbon and nitrogen were significantly influenced by various nutrient management practices during different physiological stages of crop growth.
– An attempt was made to mobilize potassium (K) from a K-bearing mineral (waste mica) inoculated ... more – An attempt was made to mobilize potassium (K) from a K-bearing mineral (waste mica) inoculated with K-solubilizing bacteria (Bacillus mucilaginosus) as a function of temperature and incubation period under in vitro laboratory conditions. A series of incubation experiments were carried out to study the mobilization of K from waste mica. Destructive samplings were drawn at different periods of incubation and analyzed for pH, total sugar content and NH 4 OAc-K. The results showed that irrespective of temperature and period of incubation, a significantly higher mobilization of K was recorded in all the treatments when incubation was carried out in the presence of the bacterial strain compared to control. The pH and total sugar content were found to decrease in the presence of Bacillus mucilaginosus as compared to control, while in the presence of the bacterial strain the NH 4 OAc-K content increased from 12.3 to 46.0%, irrespective of treatments. Thus, it may be concluded that waste mica inoculated with a K-solubilizing strain could be a promising technology to utilize waste mica, and could be used effectively as an alternative source of K-fertilizer for crop production.
Soil degradation is an age old issue as the process of agricultural practices itself. But the imp... more Soil degradation is an age old issue as the process of agricultural practices itself. But the impact of soil degradation on food production and environment is becoming more alarming than ever before due to its horizontal and vertical expansion (Durán Zuazo and Rodríguez Pleguezuelo 2008). Indiscriminate use of agro-chemicals and synthetic fertilizers is one of the responsible factors for deterioration of soil quality under modern intensive agricultural practices. In this context, adoption of agricultural practices which can support present and future food and feed demand without hampering ecosystem services is highly needed. Sustainability of a production system implies optimum yields that can be maintained with minimum or acceptable environmental consequence through sustainable management tools (Tilman et al. 2002). It is quite relevant to mention here that an organic farming practice is the only sustainable farming practice legally accepted in many countries (Diacono and Montemurro 2010). Maintenance of soil fertility and supply of plant nutrition in organic agriculture is a more complex long-term integrated approach rather than a short-term conventional one. Shifting from 'conventional' to 'organic' agriculture is not only just a replacement of synthetic chemicals with organics; rather, it also requires a greater level of management efforts and skills (Hue and Silva 2000). Organic inputs, particularly the nutrient sources, are very important and only approved sources of nutrients are allowed in the organic production system. Organic and inorganic wastes generated from farming as well industrial activities, low-grade mineral resources, sea weeds and microbes have potential to supply plant nutrients, correct soil problems and maintain soil health (Nick and Bradley 1994). The only concern regarding the use of these materials is that they need to be approved by the international regulation and certification bodies. Here the scope of alternative sources of amendments, which are approved in the organic production system, will be discussed with their nutrient supplying capacities.
Agricultural practices involving intensive applications of chemical fertilizers can be harmful to... more Agricultural practices involving intensive applications of chemical fertilizers can be harmful to the environment. Soil amendments can serve as an alternative source of plant nutrients and simultaneously improve the physical, chemical and biological properties of soils. Many soil amendments are produced from organic and inorganic waste materials. The amendment application practices therefore not only support the agricultural productivity but also facilitate an environmental friendly disposal and recycling of the wastes. This also helps the farmers to reduce their cost of production. Most of the soil amendments supply nutrients to plants over a longer period of time in a slow release process. However, best management practices should be adapted in order to harness the optimum benefits of soil amendments in agricultural and forestry production systems. This chapter already existing and/or potential applications for improving the productivity and health of soils.
Adaptive Soil Management : From Theory to Practices, 2017
Modern intensive agriculture leads to signi cant decline in soil K status due to crop removal wit... more Modern intensive agriculture leads to signi cant decline in soil K status due to crop removal without compensating through K fertilizer. Most of the K ores suit- able for commercial K fertilizer production are distributed in few countries in the northern hemisphere (Canada, Russia, Belarus and Germany). India is com- pletely dependent on foreign countries since its whole consumption of K fertil- izer is imported. So, self-suf ciency in commercial K fertilizer is a major issue in developing countries like India. In this context, alternative sources of K have a promising future in the developing countries where commercial K fertilizers are imported for crop production. There are some low-grade but indigenous resources of K-bearing minerals which can be exploited as an alternative of the expensive imported K fertilizers. Direct application of these indigenous K minerals as well as bio-activation through potassium solubilizing microorgan- isms could be a quite promising K source. In this chapter, we have discussed the scope of naturally occurring K minerals (low-grade K minerals, silicate minerals and greensand) and indigenous sources of K (crop residue, manures, wood ash and seaweed) as well as K biofertilizer as a potential substitute of commercial K fertilizer for sustainable agriculture in the developing countries
Potassium (K) is one of the essential major plant nutrients. Its importance in agriculture has in... more Potassium (K) is one of the essential major plant nutrients. Its importance in agriculture has increased with intensive agriculture as well as deficiency occurring in crop plants. Global population is increasing at a quantum rate, which pushes the targeted yield to higher levels for mitigating the food demand of hungry mouths. Production of more food material from limited land is a challenge for the researcher and it aggravates nutrient deficiency, due to more uptake of plant nutrients, especially K, by high-yielding crop varieties. Among plant nutrients, deficiency of K limits the crop growth and reduces the crop yield. The source of K is native or via various replenishment paths, i.e. crop residue, microbial biomass and a range of waste materials. Researchers mentioning the wide gap between the addition of K and removal during crop production are highlighting the challenge to maintain a sustainable crop yield. The nutrient balance in the soil system is also affected by the quantity of nutrient that is taken up, raising nutrient storage in the soil– plant–microbe system, and how much is recycled by crop residues. The use of potassium-solubilizing microorganisms (KSMs) can increase the K level in the soil solution and ultimately increase plant growth and development. The main mechanisms of KSMs are acidolysis, chelation, exchange reactions, complexolysis and organic acid production in the soil. K fertilizers cost much more than other fertilizers, so use of KSMs in agricultural crop production can be a sustainable option for enhancing in situ K availability from the fixed sink of agricultural soils.
Soil acidity is an economic and natural resource threat throughout the world. Acidification of so... more Soil acidity is an economic and natural resource threat throughout the world. Acidification of soil is a natural process with major ramifications on plant growth. As soils become more acidic, particularly when the pH drops below 4.5, it becomes increasingly difficult to produce food crops. In our country, about 25 million hectares of cultivated lands with pH value less than 5.5 are very poor in physical, chemical and biological characteristics. Naturally, nutrient availability and fixation in soil are governed by the chemical condition of soil. Knowledge and understanding about the fate of nutrient applied in soil as fertilizer are very important for improving use efficiency of applied nutrients in soil. Chemistry associated with macronutrients fixation in soil is specifically discussed here along with a brief account on how best the fixed nutrients can be utilized for plant nutrition. In aqueous systems, an acid is a substance that donates hydrogen ions or protons (H +) to some other substance. Conversely, a base is any substance that accepts H +. The H + ions or active acidity, increase with the strength of the acid. The undissociated H + contributes to a soil potential acidity. Buffer systems can maintain the pH of a solution within narrow range when small amounts of an acid or a base are added. Buffering defines the resistance to change in pH. Soils differ in terms of active and potential acidity. Also soils behave like buffered weak acids, with the H + in cation exchange complex (CEC) of humus and clay minerals providing the buffer for soil solution pH.
The main theme of this study was to evaluate the efficiency of waste mica inoculated with potassi... more The main theme of this study was to evaluate the efficiency of waste mica inoculated with potassium solubilizing bacteria (KSB) as a source of potassium. Pot culture experiment was carried out to see the release of potassium from waste mica inoculated with KSB using sudan grass (Sorghum vulgare Pers.) var Sudanensis as test crop under two Alfisols. Plant biomass yield and K uptake were studied to evaluate whether waste mica improve plant growth and nutrition or not and different pools of K in soil were studied to know how it influence the K dynamics in soil. Though application of waste mica alone improve biomass yield and K uptake over control but bio-inoculation of waste mica further improve biomass yield and K uptake. The dynamics of K in soils indicated that K was released from waste mica due to bio-inoculation in both the soils. Release kinetics of K and X-ray diffraction analysis showed significant release of K from mica treated with bacterial strain. Bacillus mucilaginosus was found most effective among the different bacterial strain. Thus bio-intervention of waste mica could an alternative source of K-fertilizer for sustaining crop production and maintaining soil potassium.
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Article by Biraj Basak
could be used as a source of K, but not as satisfactorily as commercial K fertilizers. In this context, bio-intervention (in combination with microorganisms and/or composting) of silicate minerals has been found quite promising to improve plant K availability and assimilation. This is an energy efficient and environmentally friendly approach. Here
we present a critical review of existing literature on direct application of silicate minerals as a source of K for plant nutrition as well as soil fertility enhancement by underpinning the bio-intervention strategies and related K solubilization mechanisms. An advancement of knowledge in this field will not only contribute to a better understanding of the complex natural processes of soil K fertility, but also help to develop a new approach to utilize natural mineral resources for sustainable and environmental friendly agricultural practices.
in soil different doses of each micronutrient were applied to isabgol under pot culture experiment. Biomass and seed yield of isabgol was improved significantly with the application of micronutrients. Quality parameters like test weight, isabgol husk percentage and swelling property of husk were found to improve with micronutrient application.
Application of Zn, Cu, Fe and Mn increased isabgol husk yield up to 3.13, 2.11, 3.11 and 1.98 % respectively. Micronutrient treatment significantly increased their content and uptake by isabgol under pot culture experiment while soil micronutrient status was improved after harvesting of the crop. So it was found from the study that micronutrient application not only improved yield and quality of isabgol but also maintained the soil micronutrient status. The micronutrient fertilizers supply particular micronutrient to the soil available pool of micronutrient which helps in maintaining micronutrient status in soil for next crop.
straw as an alternative sources of phosphorus. Three different sources of low-grade RP namely Udaipur,
Jhabua and Purulia were evaluated for alternative source of P. Total carbon (C) decreased while total
nitrogen (N) increased, leading to a decrease in the C/N ratio at the end of composting. Notable increases
in total and available P was found in the composts charged with RPs. The rate of P released from the
composts was studied through leaching experiment in the laboratory. An incubation study was carried out
to evaluate the effect of different compost on soil P availability. Data revealed that the sharp increase in
water soluble P from all the compost at 14 days of leaching then a gradual decrease. Significantly higher
water soluble P released from the value added (RP charged) compost as compared to ordinary compost
throughout the leaching period. Application of value added compost in soil increased water soluble,
available P, microbial biomass C and P as well as acid and alkaline phosphatase activity in soil. Initially,
the value added compost showed lower available P as compared to DAP however, improved significantly
at a later stage of incubation. The increase in different labile pools of P in soil amended with value added
compost also indicates substantial amount of P mobilized from the compost during incubation. Thus, the
value added compost could be an effective alternative of chemical fertilizer and promising technology to
utilize low-grade RP as P source.
sub-tropical India to evaluate the effect of value added manures and fertilizers on soil health, grain quality and enzyme activities under maize-wheat rotation. Eight treatments consisting of three organic manures (vermicompost, NADEP compost and farm yard manure) and fertilizers in different combinations were applied. The highest dehydrogenase
activity (18.87 and 17.97 μg triphenylformazan g-1 soil h-1 in maize and wheat, respectively) was reflected under integrated application of organic and fertilizers, whereas the highest urease activity (7.76 and 9.43 μg urea g-1 h-1 in maize and wheat,respectively) was observed in 100% NPK. Application of 50% NPK along with organic manures significantly improved grain yield and mineral composition. Grain protein content and weight of maize and wheat were higher under integrated nutrient management and 100% NPK. Microbial biomass carbon and nitrogen were significantly influenced by various nutrient management practices during different physiological stages of crop growth.
could be used as a source of K, but not as satisfactorily as commercial K fertilizers. In this context, bio-intervention (in combination with microorganisms and/or composting) of silicate minerals has been found quite promising to improve plant K availability and assimilation. This is an energy efficient and environmentally friendly approach. Here
we present a critical review of existing literature on direct application of silicate minerals as a source of K for plant nutrition as well as soil fertility enhancement by underpinning the bio-intervention strategies and related K solubilization mechanisms. An advancement of knowledge in this field will not only contribute to a better understanding of the complex natural processes of soil K fertility, but also help to develop a new approach to utilize natural mineral resources for sustainable and environmental friendly agricultural practices.
in soil different doses of each micronutrient were applied to isabgol under pot culture experiment. Biomass and seed yield of isabgol was improved significantly with the application of micronutrients. Quality parameters like test weight, isabgol husk percentage and swelling property of husk were found to improve with micronutrient application.
Application of Zn, Cu, Fe and Mn increased isabgol husk yield up to 3.13, 2.11, 3.11 and 1.98 % respectively. Micronutrient treatment significantly increased their content and uptake by isabgol under pot culture experiment while soil micronutrient status was improved after harvesting of the crop. So it was found from the study that micronutrient application not only improved yield and quality of isabgol but also maintained the soil micronutrient status. The micronutrient fertilizers supply particular micronutrient to the soil available pool of micronutrient which helps in maintaining micronutrient status in soil for next crop.
straw as an alternative sources of phosphorus. Three different sources of low-grade RP namely Udaipur,
Jhabua and Purulia were evaluated for alternative source of P. Total carbon (C) decreased while total
nitrogen (N) increased, leading to a decrease in the C/N ratio at the end of composting. Notable increases
in total and available P was found in the composts charged with RPs. The rate of P released from the
composts was studied through leaching experiment in the laboratory. An incubation study was carried out
to evaluate the effect of different compost on soil P availability. Data revealed that the sharp increase in
water soluble P from all the compost at 14 days of leaching then a gradual decrease. Significantly higher
water soluble P released from the value added (RP charged) compost as compared to ordinary compost
throughout the leaching period. Application of value added compost in soil increased water soluble,
available P, microbial biomass C and P as well as acid and alkaline phosphatase activity in soil. Initially,
the value added compost showed lower available P as compared to DAP however, improved significantly
at a later stage of incubation. The increase in different labile pools of P in soil amended with value added
compost also indicates substantial amount of P mobilized from the compost during incubation. Thus, the
value added compost could be an effective alternative of chemical fertilizer and promising technology to
utilize low-grade RP as P source.
sub-tropical India to evaluate the effect of value added manures and fertilizers on soil health, grain quality and enzyme activities under maize-wheat rotation. Eight treatments consisting of three organic manures (vermicompost, NADEP compost and farm yard manure) and fertilizers in different combinations were applied. The highest dehydrogenase
activity (18.87 and 17.97 μg triphenylformazan g-1 soil h-1 in maize and wheat, respectively) was reflected under integrated application of organic and fertilizers, whereas the highest urease activity (7.76 and 9.43 μg urea g-1 h-1 in maize and wheat,respectively) was observed in 100% NPK. Application of 50% NPK along with organic manures significantly improved grain yield and mineral composition. Grain protein content and weight of maize and wheat were higher under integrated nutrient management and 100% NPK. Microbial biomass carbon and nitrogen were significantly influenced by various nutrient management practices during different physiological stages of crop growth.